Heat sink



FIG. 1 is a front elevation view of a first embodiment of a heat sink according to our new design;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a right side elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a perspective view thereof;

FIG. 8 is another perspective view thereof;

FIG. 9 is another front elevation view thereof;

FIG. 10 is a sectional view along A—A′ in FIG. 9;

FIG. 11 is a front elevation view of a second embodiment of a heat sink according to a modification of our new design;

FIG. 12 is a rear elevation view thereof;

FIG. 13 is a right side elevation view thereof;

FIG. 14 is a left side elevation view thereof;

FIG. 15 is a top plan view thereof;

FIG. 16 is a bottom plan view thereof;

FIG. 17 is a perspective view thereof;

FIG. 18 is another perspective view thereof;

FIG. 19 is another front elevation view thereof;

FIG. 20 is a sectional view along A—A′ in FIG. 19;

FIG. 21 is a front elevation view of a third embodiment of a heat sink according to another modification of our new design;

FIG. 22 is a rear elevation view thereof;

FIG. 23 is a right side elevation view thereof;

FIG. 24 is a left side elevation view thereof;

FIG. 25 is a top plan view thereof;

FIG. 26 is a bottom plan view thereof;

FIG. 27 is a perspective view thereof;

FIG. 28 is another perspective view thereof;

FIG. 29 is a front elevation view of a fourth embodiment of a heat sink according to another modification of our new design;

FIG. 30 is a rear elevation view thereof;

FIG. 31 is a right side elevation view thereof;

FIG. 32 is a left side elevation view thereof;

FIG. 33 is a top plan view thereof;

FIG. 34 is a bottom plan view thereof;

FIG. 35 is a perspective view thereof; and,

FIG. 36 is another perspective view thereof. 

The ornamental design for a heat sink, as shown and described. 